The molecules from IEDs (e.g. nitroaromatic, nitramine, and nitrate ester compounds) easily blend with other contaminants in the ambient, decompose rapidly producing various ionized species, and have relatively low vapor pressures compared to other compounds. Consequently, IED compounds (nitroamine, nitroaromatic, and nitrate ester compounds) are hard to detect with precision. Most of the platforms to detect explosive compounds successfully are gas chromatography (GC), ion mobility spectrometry (IMS), and mass spectrometry (MS) within the most frequently used analytical methods. However, the integration of such analytical techniques in the processing of thin film technologies for detecting IED compounds is still under development.
The “electronic nose” concept has also been widely used to investigate new technologies for sensing organic compounds. Most of those technologies have been developed to induce both flexibility and conductivity, and even though there have been important breakthroughs in the field of conducting/flexible films, many challenges such as film transparency and high sensitivity and selectivity are still to be overcome.
New strategies are needed to develop composites that combine conductive components that are embedded in translucid matrices. The challenges are to use the lowest amount of metallic filler without compromising conductivity and develop processing techniques that render adaptability and lower production costs. Despite the tremendous market potential for such films, we lack the fundamental understanding as to how to combine and process such materials to optimize desirable properties, such as flexibility, robustness, and transparency as well as specificity and rate of detection.